U.S. patent number 8,766,511 [Application Number 13/212,123] was granted by the patent office on 2014-07-01 for method and system for distributed network of nanoparticle ink based piezoelectric sensors for structural health monitoring.
This patent grant is currently assigned to The Boeing Company. The grantee listed for this patent is Jeffrey Lynn Duce, Scott Robert Johnston. Invention is credited to Jeffrey Lynn Duce, Scott Robert Johnston.
United States Patent |
8,766,511 |
Duce , et al. |
July 1, 2014 |
Method and system for distributed network of nanoparticle ink based
piezoelectric sensors for structural health monitoring
Abstract
The disclosure provides in one embodiment a system for
monitoring structural health of a structure. The system has a
structure to be monitored for structural health. The system further
has a distributed network of nanoparticle ink based piezoelectric
sensor assemblies deposited onto the structure. Each assembly has a
plurality of nanoparticle ink based piezoelectric sensors and a
plurality of conductive ink power and communication wire assemblies
interconnecting the plurality of sensors. The system further has an
ink deposition apparatus depositing the distributed network of
nanoparticle ink based piezoelectric sensor assemblies onto the
structure. The system further has an electrical power source
providing electrical power to the distributed network. The system
further has a data communications network retrieving and processing
structural health data of the structure via one or more signals
from the sensors.
Inventors: |
Duce; Jeffrey Lynn (Milton,
WA), Johnston; Scott Robert (St. Louis, MO) |
Applicant: |
Name |
City |
State |
Country |
Type |
Duce; Jeffrey Lynn
Johnston; Scott Robert |
Milton
St. Louis |
WA
MO |
US
US |
|
|
Assignee: |
The Boeing Company (Chicago,
IL)
|
Family
ID: |
47010168 |
Appl.
No.: |
13/212,123 |
Filed: |
August 17, 2011 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20130044155 A1 |
Feb 21, 2013 |
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Current U.S.
Class: |
310/338; 73/778;
310/319; 310/328 |
Current CPC
Class: |
G01N
29/2475 (20130101); G01M 5/0083 (20130101); H01L
41/314 (20130101); H01L 41/1132 (20130101); G01M
5/0033 (20130101); B82Y 30/00 (20130101); G01N
2291/2694 (20130101); G01N 2291/0258 (20130101); G01N
2291/0231 (20130101); G01N 2291/106 (20130101) |
Current International
Class: |
H01L
41/113 (20060101) |
Field of
Search: |
;310/318,319,328,339,338
;702/39 ;73/646,778 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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WO-2005069858 |
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Aug 2005 |
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WO |
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Other References
Francesca Bortolani et al., "Molten salt synthesis of PZT powder
for direct write inks", Journal of the European Ceramic Society 30
(2010) pp. 2073-2079. cited by applicant .
K. Byrappa et al., Handbook of Hydrothermal Technology, A
Technology for Crystal Growth and Materials Processing, Noyes
Publications, Park Ridge, New Jersey, William Andrew Publishing,
LLC, Norwich, New York (2001), 12 pages (first page of each
chapter). cited by applicant .
R.N. Das et al., "In Situ Synthesis of Nanosized PZT Powders in the
Precursor Material and the Influence of Particle Size on the
Dielectric Property", NanoStructured Materials, vol. 10, No. 8
(1998) pp. 1371-1377. cited by applicant .
Yuan Deng et al., "Hydrothermal synthesis and characterization of
nanocrystalline PZT powders", Materials Letters 57 (2003) pp.
1675-1678. cited by applicant .
Jessie Sungyun Jeon, "Optimization of PZT processing using thermal
ink-jet printing", Master's Thesis, Massachusetts Institute of
Technology, Jun. 2008, 29 pages. cited by applicant .
Zhong-Cheng Qiu et al., "Hydrothermal synthesis of
Pb(Zr0.52Ti0.48)O3 powders at low temperature and low alkaline
concentration", Bull. Mater. Sci., vol. 32, No. 2 (2009) pp.
193-197. cited by applicant .
B. Su et al., "Control of the particle size and morphology of
hydrothermally synthesized lead zirconate titanate powder", Journal
of Materials Science 39 (2004) pp. 6439-6447. cited by applicant
.
Maria Traianidis et al., "Hydrothermal Synthesis of Lead Zirconium
Titanate (PZT) Powders and their Characteristics", Journal of the
European Ceramic Society 19 (1999) pp. 1023-1026. cited by
applicant .
S.F. Wang et al., "Characterization of hydrothermally synthesized
lead zirconate titanate (PZT) ceramics", Materials Chemistry and
Physics 87 (2004) pp. 53-58. cited by applicant .
John S. Dodds et al., "Pieozoelectric Characterization of PVDF-TrFE
Thin Films Enhanced With ZnO Nanoparticles", IEEE Sensors Journal,
vol. 12, No. 6, Jun. 2012, pp. 1889-1890. cited by applicant .
Yirong Lin et al., "Enhanced Piezoelectric Properties of Lead
Zirconate Titanate Sol-gel Derived Ceramics Using Single Crystal
PbZr0.52Ti0.48O3 Cubes", Journal of Applied Physics, 108 (2010),
pp. 064108-1 to 064108-6. cited by applicant .
Kenneth J. Loh et al., "Zinc Oxide Nanoparticle-Polymeric Thin
Films for Dynamic Strain Sensing", Journal of Materials Science,
vol. 46 (2011) pp. 228-237. cited by applicant .
Zhihong Wang et al., "Dense PZT Thick Films Derived from Sol-gel
Based Nanocomposite Process", Materials Science and Engineering,
Elsevier, vol. B99 (2003) pp. 56-62. cited by applicant .
EPO European Search Report for Counterpart EP Application No.
12175708.2, Nov. 11, 2012, 7 pages. cited by applicant.
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Primary Examiner: Dougherty; Thomas
Claims
What is claimed is:
1. A system for monitoring structural health of a structure, the
system comprising: a structure to be monitored for structural
health; a distributed network of nanoparticle ink based
piezoelectric sensor assemblies deposited directly onto the
structure with a nanoparticle ink deposited via an ink deposition
direct write printing process, each assembly comprising: a
plurality of nanoparticle ink based piezoelectric sensors; and, a
plurality of conductive ink power and communication wire assemblies
interconnecting the plurality of sensors; an ink deposition direct
write printing apparatus depositing the distributed network of
nanoparticle ink based piezoelectric sensor assemblies directly
onto the structure and without use of an adhesive; an electrical
power source providing electrical power to the distributed network;
and, a data communications network retrieving and processing
structural health data of the structure via one or more signals
from the sensors.
2. The system of claim 1, further comprising a voltage supply
source poling the plurality of nanoparticle ink based piezoelectric
sensors.
3. The system of claim 1, wherein the structure comprises a
material selected from a group comprising a composite material, a
metallic material, and a combination of a composite material and a
metallic material.
4. The system of claim 1, wherein the structure has a curved
surface on which the distributed network of nanoparticle ink based
piezoelectric sensor assemblies is deposited.
5. The system of claim 1, wherein the nanoparticle ink based
piezoelectric sensors are deposited onto the structure in a
customized shape.
6. The system of claim 1, wherein the ink deposition direct write
printing apparatus comprises one of a jetted atomized deposition
apparatus, an ink jet printing apparatus, an aerosol printing
apparatus, a pulsed laser evaporation apparatus, a flexography
printing apparatus, a micro-spray printing apparatus, a flat bed
silk screen printing apparatus, a rotary silk screen printing
process, and a gravure printing process.
7. The system of claim 1, wherein the distributed network of
nanoparticle ink based piezoelectric sensor assemblies further
comprises an insulation layer deposited directly onto a body of the
structure comprising a metallic structure.
8. The system of claim 1, wherein each of the conductive ink power
and communication wire assemblies comprises a first conductive
electrode, a second conductive electrode, a first conductive trace
wire, and a second conductive trace wire.
9. The system of claim 1, wherein the structural health data
comprises disbonds, weak bonding, strain levels, moisture
ingression, materials change, cracks, voids, delamination,
porosity, and irregularities that adversely affect performance of
the structure.
10. The system of claim 1, wherein the nanoparticle ink based
piezoelectric sensors are comprised of nanoparticles having a
particle size in a range of from about 20 nanometers to about 1
micron.
11. The system of claim 1, wherein the structure comprises an
aircraft structure.
12. A method of monitoring structural health of a structure, the
method comprising: providing a structure to be monitored for
structural health; depositing directly onto the structure with a
nanoparticle ink deposited via an ink deposition direct write
printing process a plurality of nanoparticle ink based
piezoelectric sensors and a plurality of conductive ink power and
communication wire assemblies interconnecting the plurality of
sensors to form a distributed network of nanoparticle ink based
piezoelectric sensor assemblies; providing electrical power to the
distributed network via an electrical power source; and, using a
data communications network to retrieve and process structural
health data of the structure via one or more signals from the
sensors.
13. The method of claim 12, further comprising after depositing the
plurality of nanoparticle ink based piezoelectric sensors, poling
the nanoparticle ink based piezoelectric sensors with a voltage
supply source to create an electric field across the nanoparticle
ink based piezoelectric sensors.
14. The method of claim 12, wherein the ink deposition direct write
printing process comprises one of a jetted atomized deposition
process, an ink jet printing process, an aerosol printing process,
a pulsed laser evaporation process, a flexography printing process,
a micro-spray printing process, a flat bed silk screen printing
process, a rotary silk screen printing process, and a gravure
printing process.
15. The method of claim 12, wherein the data communications network
retrieves data received from the nanoparticle ink based
piezoelectric sensors with a receiver and processes data received
from the nanoparticle ink based piezoelectric sensors with a
computer processor.
16. The method of claim 12, wherein the structural health data
comprises disbonds, weak bonding, strain levels, moisture
ingression, materials change, cracks, voids, delamination,
porosity, and irregularities that adversely affect performance of
the structure.
17. A structure to be monitored for structural health, the
structure comprising: a body; and, a distributed network of
nanoparticle ink based piezoelectric sensor assemblies deposited
directly onto the body of the structure with a nanoparticle ink
deposited via an ink deposition direct write printing process, each
assembly comprising: a plurality of nanoparticle ink based
piezoelectric sensors; and, a plurality of conductive ink actuator
assemblies interconnecting the plurality of sensors, wherein a
signal path within the distributed network comprises a plurality of
nanoparticles and structural health data of the structure is
obtained via one or more signals from the nanoparticle ink based
piezoelectric sensors flowing through the signal path to a data
communications network.
18. The structure of claim 17, wherein the structure has a curved
surface on which the distributed network of nanoparticle ink based
piezoelectric sensor assemblies is deposited.
19. The structure of claim 17, wherein the distributed network of
nanoparticle ink based piezoelectric sensor assemblies further
comprises an insulation layer deposited directly onto the body of
the structure comprising a metallic structure.
20. The structure of claim 17, wherein the nanoparticle ink based
piezoelectric sensors are comprised of nanoparticles having a
particle size in a range of from about 20 nanometers to about 1
micron.
21. The structure of claim 17, wherein the ink deposition direct
write printing process comprises one of a jetted atomized
deposition process, an ink jet printing process, an aerosol
printing process, a pulsed laser evaporation process, a flexography
printing process, a micro-spray printing process, a flat bed silk
screen printing process, a rotary silk screen printing process, and
a gravure printing process.
22. The structure of claim 17, wherein the structure comprises an
aircraft structure.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
This nonprovisional patent application is related to
contemporaneously filed U.S. nonprovisional patent application Ser.
No. 13/211,554, titled "METHODS FOR FORMING LEAD ZIRCONATE TITANATE
NANOPARTICLES", filed on Aug. 17, 2011, and this nonprovisional
patent application is also related to contemporaneously filed U.S.
nonprovisional patent application Ser. No. 13/212,037, titled
"METHOD AND SYSTEM OF FABRICATING PZT NANOPARTICLE INK BASED
PIEZOELECTRIC SENSOR", filed on Aug. 17, 2011. The contents of both
of these contemporaneously filed U.S. nonprovisional patent
applications are hereby incorporated by reference in their
entireties.
BACKGROUND
1) Field of the Disclosure
The disclosure relates generally to structural health monitoring
methods and systems, and more particularly, to structural health
monitoring methods and systems using nanoparticle sensors deposited
onto a surface of a structure.
2) Description of Related Art
Small sensors, such as microsensors, may be used in a variety of
applications including in structural health monitoring (SHM)
systems and methods to continuously monitor structures, such as
composite or metal structures, and to measure material
characteristics and stress and strain levels in order to assess
performance, possible damage, and current state of the structures.
Known SHM systems and methods may include the use of small, stiff,
ceramic disk sensors integrated onto a polyimide substrate or other
suitable substrate. Such known sensors are typically manually
bonded to a structure with an adhesive. Such manual installation
may increase labor and installation costs and such adhesive may
degrade over time and may result in the sensor disbonding from the
structure. In addition, such known sensors may be made of rigid,
planar, and/or brittle materials that may limit their usage, for
example, usage on a curved or non-planar substrate surface may be
difficult. Moreover, such ceramic disk sensors require power and
communication wiring with a minimum of two wires connected to each
sensor. Such wiring may require connection and management with the
use of wire ties, hangars, brackets, or other hardware to maintain
organization of the wiring. Such wiring and hardware to manage and
organize the wiring may increase the complexity and the weight of
the structure.
In addition, known sensor systems and methods, such as
micro-electromechanical systems (MEMS) and methods, may include the
use of depositing onto a substrate piezoelectric sensors, such as
lead zirconate titanate (PZT) sensors, having nanoparticles. Known
methods for making such MEMS may include molten salt synthesis of
PZT powder for direct write inks. However, the applications of the
PZT sensors fabricated with such known methods may be limited by
the physical geometry of the PZT sensors. Such physical geometry
limitations may result in inadequate sensing capacities or
inadequate actuation responses. Further, the PZT sensors fabricated
with such known methods may be unable to be applied or located in
areas where their function may be important due to the PZT sensor
fabrication method. For example, known molten salt synthesis
methods may require processing at higher temperatures than certain
application substrates can tolerate.
Further, such known MEMS systems and methods may also include the
use of sensors having nanoparticles which have not been
crystallized and which may be less efficient than nanoparticles
which have been crystallized. Non-crystallized structures typically
have greater disorganization resulting in decreased response
sensitivity to strain and voltage, whereas crystallized structures
typically have greater internal organization resulting in increased
response sensitivity to strain and decreased necessity for energy
to operate. In addition, the nanoparticles of the sensors may be
too large for some known deposition processes and systems, such as
a jetted atomized deposition (JAD) process, and such nanoparticles
may require a high temperature sintering/crystallization process
which may result in damage to temperature sensitive substrates or
structures.
Accordingly, there is a need in the art for an improved method and
system for a distributed network of nanoparticle piezoelectric
sensors that may be used in structural health monitoring systems
and methods for structures, where such improved method and system
provide advantages over known methods and systems.
SUMMARY
This need for an improved method and system for a distributed
network of nanoparticle piezoelectric sensors that may be used in
structural health monitoring systems and methods for structures is
satisfied. As discussed in the below detailed description,
embodiments of the system and method may provide significant
advantages over existing systems and methods.
In an embodiment of the disclosure, there is provided a system for
monitoring structural health of a structure. The system comprises a
structure to be monitored for structural health. The system further
comprises a distributed network of nanoparticle ink based
piezoelectric sensor assemblies deposited onto the structure. Each
assembly comprises a plurality of nanoparticle ink based
piezoelectric sensors. Each assembly further comprises a plurality
of conductive ink power and communication wire assemblies
interconnecting the plurality of sensors. The system further
comprises an ink deposition apparatus depositing the distributed
network of nanoparticle ink based piezoelectric sensor assemblies
onto the structure. The system further comprises an electrical
power source providing electrical power to the distributed network.
The system further comprises a data communications network
retrieving and processing structural health data of the structure
via one or more signals from the sensors. The structure may have a
non-curved or planar surface, a curved or non-planar surface, or a
combination of a non-curved or planar surface and a curved or
non-planar surface. The nanoparticle ink based piezoelectric sensor
assemblies may be deposited onto a surface of the structure with
one or more layers of insulation, coatings, or paint in between a
body of the structure and the sensor assemblies.
In another embodiment of the disclosure, there is provided a method
of monitoring structural health of a structure. The method
comprises providing a structure to be monitored for structural
health. The method further comprises depositing onto the structure
via an ink deposition process a plurality of nanoparticle ink based
piezoelectric sensors and a plurality of conductive ink power and
communication wire assemblies interconnecting the plurality of
sensors to form a distributed network of nanoparticle ink based
piezoelectric sensor assemblies. The method further comprises
providing electrical power to the distributed network via an
electrical power source. The method further comprises using a data
communications network to retrieve and process structural health
data of the structure via one or more signals from the sensors.
In another embodiment of the disclosure, there is provided a
structure to be monitored for structural health. The structure
comprises a body. The structure further comprises a distributed
network of nanoparticle ink based piezoelectric sensor assemblies
deposited onto the body of the structure via an ink deposition
process. Each assembly comprises a plurality of nanoparticle ink
based piezoelectric sensors. Each assembly further comprises a
plurality of conductive ink actuator assemblies interconnecting the
plurality of sensors. A signal path within the distributed network
comprises a plurality of nanoparticles and structural health data
of the structure is obtained via one or more signals from the
sensors flowing through the signal path to a data communications
network.
In another embodiment of the disclosure, there is provided a method
of monitoring structural health of a structure. The method
comprises providing a structure to be monitored for structural
health. The method further comprises using a distributed network of
nanoparticle ink based piezoelectric sensor assemblies to sense and
monitor the structural health of the structure. The method further
comprises providing electrical power to the distributed network via
an electrical power source. The method further comprises using a
data communications network to retrieve and process structural
health data of the structure via one or more signals from the
nanoparticle ink based piezoelectric sensor assemblies sensors.
The features, functions, and advantages that have been discussed
can be achieved independently in various embodiments of the
disclosure or may be combined in yet other embodiments further
details of which can be seen with reference to the following
description and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The disclosure can be better understood with reference to the
following detailed description taken in conjunction with the
accompanying drawings which illustrate preferred and exemplary
embodiments, but which are not necessarily drawn to scale,
wherein:
FIG. 1 is an illustration of a perspective view of an exemplary
aircraft for which one of the embodiments of the system and method
of the disclosure may be used;
FIG. 2 is an illustration of a cross-sectional view of one of the
embodiments of a deposited nanoparticle ink based piezoelectric
sensor assembly;
FIG. 3 is an illustration of a cross-sectional view of another one
of the embodiments of a deposited nanoparticle ink based
piezoelectric sensor assembly;
FIG. 4 is an illustration of a top perspective view of one of the
embodiments of a deposited distributed network of nanoparticle ink
based piezoelectric sensor assemblies;
FIG. 5 is an illustration of a block diagram of one of the
embodiments of a structure having a distributed network of
nanoparticle ink based piezoelectric sensor assemblies of the
disclosure;
FIG. 6A is an illustration of a schematic view of one of the
embodiments of an ink deposition process and apparatus for
fabricating a nanoparticle ink based piezoelectric sensor of the
disclosure;
FIG. 6B is an illustration of a close-up view of the piezoelectric
nanoparticle ink based sensor being deposited onto the surface of a
substrate;
FIG. 7 is an illustration of a schematic diagram of one of the
embodiments of a structural health monitoring system using the
distributed network of nanoparticle ink based piezoelectric sensor
assemblies of the disclosure;
FIG. 8 is an illustration of a flow diagram of an embodiment of a
method of the disclosure; and,
FIG. 9 is an illustration of a block diagram of embodiments of the
ink deposition processes and ink deposition apparatuses that may be
used in the system and method disclosed herein.
DETAILED DESCRIPTION
Disclosed embodiments will now be described more fully hereinafter
with reference to the accompanying drawings, in which some, but not
all of the disclosed embodiments are shown. Indeed, several
different embodiments may be provided and should not be construed
as limited to the embodiments set forth herein. Rather, these
embodiments are provided so that this disclosure will be thorough
and complete and will fully convey the scope of the disclosure to
those skilled in the art. The following detailed description is of
the best currently contemplated modes of carrying out the
disclosure. The description is not to be taken in a limiting sense,
but is made merely for the purpose of illustrating the general
principles of the disclosure, since the scope of the disclosure is
best defined by the appended claims.
Now referring to the Figures, FIG. 1 is an illustration of a
perspective view of an exemplary prior art aircraft 10 for which
one of the embodiments of a distributed network of nanoparticle ink
based piezoelectric sensor assemblies 120 (see FIG. 5) of a
structure 30 may be used, as well as for which a system 170 (see
FIG. 7) and a method 200 (see FIG. 8) for structural health
monitoring using nanoparticle ink based piezoelectric sensors 110
(see FIGS. 2-4) may be used. The aircraft 10 comprises a fuselage
12, a nose 14, a cockpit 16, wings 18 operatively coupled to the
fuselage 12, one or more propulsion units 20, a tail vertical
stabilizer 22, and one or more tail horizontal stabilizers 24.
Although the aircraft 10 shown in FIG. 1 is generally
representative of a commercial passenger aircraft, the system 170
and method 200 disclosed herein may also be employed in other types
of aircraft. More specifically, the teachings of the disclosed
embodiments may be applied to other passenger aircraft, cargo
aircraft, military aircraft, rotorcraft, and other types of
aircraft or aerial vehicles, as well as aerospace vehicles such as
satellites, space launch vehicles, rockets, and other types of
aerospace vehicles. It may also be appreciated that embodiments of
systems, methods and apparatuses in accordance with the disclosure
may be utilized in other vehicles, such as boats and other
watercraft, trains, automobiles, trucks, buses, and other types of
vehicles. It may also be appreciated that embodiments of systems,
methods and apparatuses in accordance with the disclosure may be
utilized in architectural structures, turbine blades, medical
devices, electronic actuation equipment, consumer electronic
devices, vibratory equipment, passive and active dampers, or other
suitable structures.
As shown in FIG. 7, in an embodiment of the disclosure, there is
provided a structural health monitoring system 170 for monitoring
structural health 172 of a structure 30. FIG. 7 is an illustration
of a block diagram of one of the embodiments of the structural
health monitoring system 170 using the nanoparticle ink based
piezoelectric sensors 110 of the disclosure. The system 170
comprises a structure 30 to be monitored for structural health 172.
The system 170 further comprises a distributed network of
nanoparticle ink based piezoelectric sensor assemblies 120
deposited onto a surface of the structure 30. The distributed
network of nanoparticle ink based piezoelectric sensor assemblies
120 may be deposited onto a surface of the structure 30 with one or
more layers of insulation, coatings, or paint in between a body 32
(see FIG. 5) of the structure 30 and the distributed network of
nanoparticle ink based piezoelectric sensor assemblies 120.
Each sensor assembly 120 comprises a plurality of nanoparticle ink
based piezoelectric sensors 110. Each sensor assembly 120 further
comprises a plurality of conductive ink power and communication
wire assemblies 140, acting as actuator assemblies 141,
interconnecting the plurality of nanoparticle ink based
piezoelectric sensors 110. The structural health monitoring system
170 preferably comprises a deposited nanoparticle ink based
piezoelectric sensor assembly 115 (see also FIGS. 2 and 3). In one
embodiment the deposited nanoparticle ink based piezoelectric
sensor assembly 115 may comprise a deposited nanoparticle ink based
piezoelectric sensor assembly 116 (see FIG. 2), if used with the
composite structure 102, and may comprise a deposited nanoparticle
ink based piezoelectric sensor assembly 130 (see FIG. 3), if used
with a metallic structure 132. As shown in FIG. 7, the structural
health monitoring system 170 further comprises an ink deposition
apparatus 142 depositing the distributed network of nanoparticle
ink based piezoelectric sensor assemblies 120 onto a surface of the
structure 30. The structural health monitoring system 170 may
further comprise a voltage supply source 176 for poling the
plurality of sensors 110. The voltage supply source 176 may be used
for poling the nanoparticle ink based piezoelectric sensors 110
prior to use in the structural health monitoring system 170. As
used herein, the term "poling" means a process by which a strong
electric field is applied across a material, usually at elevated
temperatures, in order to orient or align dipoles or domains. The
voltage supply source 176 may also drive some piezoelectric sensors
110 so that they become actuators 141 sending interrogating signals
to other piezoelectric sensors 110.
As shown in FIG. 7, the structural health monitoring system 170
further comprises an electrical power source 178 providing
electrical power to the sensor assembly 120. The electrical power
source 178 may comprise batteries, voltage, RFID (radio frequency
identification), magnetic induction transmission, or another
suitable electrical power source. The electrical power source 178
may be wireless. As shown in FIG. 7, the structural health
monitoring system 170 further comprises a data communications
network 179 for retrieving and processing structural health data
174 of the structure 30 via one or more signals 92 from the sensors
110. The data communications network 179 may be wireless. The data
communications network 179 may be digital or analog. The data
communications network 179 may retrieve data received from the
nanoparticle ink based piezoelectric sensors 110, such as with a
receiver 175 (see FIG. 7), and may process data received from the
nanoparticle ink based piezoelectric sensors 110, such as with a
computer processor 177 (see FIG. 7). The data communications
network 179 may be wireless.
The deposition of the nanoparticle ink based piezoelectric sensors
110 onto a surface of the substrate 101 or onto a surface of the
structure 30 (see FIG. 7) enables in situ installation of the
nanoparticle ink based piezoelectric sensors 110 for applications
such as structural health monitoring. The nanoparticle ink based
piezoelectric sensors 110 may be a key enabler of high density
structural health monitoring systems 170. Two or more nanoparticle
ink based piezoelectric sensors 110 may be used to enable the
structural health monitoring system 170 for monitoring structural
health 172 of a structure 30, such as a composite structure 102
(see FIG. 1) or a metallic structure 132 (see FIG. 3), or another
suitable structure, and for providing structural health data 174.
The structural health data 174 may comprise disbonds, weak bonding,
strain levels, moisture ingression, materials change, cracks,
voids, delamination, porosity, or other suitable structural health
data 174 or electromechanical properties or other irregularities
which may adversely affect the performance of the structure 30.
The structure 30 preferably comprises a material comprising a
composite material, a metallic material, or a combination of a
composite material and a metallic material. The structure 30
preferably has a curved surface 138 on which the distributed
network of nanoparticle ink based piezoelectric sensor assemblies
120 is deposited. The nanoparticle ink based piezoelectric sensors
110 may be deposited onto the structure 30 in a customized shape
164 (see FIG. 6B). As shown in FIG. 9, the ink deposition apparatus
142 may comprise a direct write printing apparatus 144 comprising a
jetted atomized deposition apparatus 146, an ink jet printing
apparatus 147, an aerosol printing apparatus 190, a pulsed laser
evaporation apparatus 192, a flexography printing apparatus 194, a
micro-spray printing apparatus 196, a flat bed silk screen printing
apparatus 197, a rotary silk screen printing apparatus 198, a
gravure printing apparatus 199, or another suitable direct write
printing apparatus 144. The distributed network of nanoparticle ink
based piezoelectric sensor assemblies 120 may further comprise an
insulation layer 134 deposited onto a surface of the structure 30.
As shown in FIGS. 2 and 3, the conductive ink power and
communication wire assemblies 140 preferably comprise a first
conductive electrode 114, a second conductive electrode 118, a
first conductive trace wire 112a, and a second conductive trace
wire 112b. The structural health data 174 may comprise disbonds,
weak bonding, strain levels, moisture ingression, materials change,
cracks, voids, delamination, porosity, and irregularities that
adversely affect the performance of the structure 30. The
nanoparticle ink based piezoelectric sensors 110 are preferably
comprised of nanoparticles having a particle size in a range of
from about 20 nanometers to about 1 micron. The structure 30
preferably comprises an aircraft structure 10 (see FIG. 1).
As shown in FIG. 5, in another embodiment of the disclosure, there
is provided a structure 30 to be monitored for structural health
172 (see FIG. 7). FIG. 5 is an illustration of a block diagram of
one of the embodiments of the structure 30 of the disclosure. The
structure 30 comprises a body 32. The structure 30 further
comprises a distributed network of nanoparticle ink based
piezoelectric sensor assemblies 120 deposited onto a surface of the
structure 30 via an ink deposition process 122. Each sensor
assembly 120 comprises a plurality of nanoparticle ink based
piezoelectric sensors 110. Each sensor assembly 120 further
comprises a plurality of conductive ink actuator assemblies 141
interconnecting the plurality of nanoparticle ink based
piezoelectric sensors 110. A signal path 90 within the sensor
assembly 120 comprises a plurality of nanoparticles. Structural
health data 174 (see FIG. 7) of the structure 30 is preferably
obtained via one or more signals 92 from the nanoparticle ink based
piezoelectric sensors 110 flowing through the signal path 90 to a
data communications network 179 (see FIG. 7).
The nanoparticle ink based piezoelectric sensors 110 may comprise a
nanoparticle ink such as a formulated lead zirconate titanate (PZT)
ink, barium titanate (BaTiO.sub.3), or another suitable
nanoparticle ink. The ink preferably comprises nanoscale ink
nanoparticles. Preferably, the nanoscale ink nanoparticles are
pre-crystallized. The nanoparticle ink preferably has a nanoscale
particle size in a range of from about 20 nanometers to about 1
micron. The nanoscale ink particles size allows for the
nanoparticle ink to be deposited using a wide range of ink
deposition processes, apparatuses, and systems, and in particular,
allows for the nanoparticle ink to be deposited using a jetted
atomized deposition process 126 (see FIGS. 6A and 9) and a jetted
atomized deposition apparatus 146 (see FIGS. 6A and 9). Each of the
nanoparticle ink based piezoelectric sensor 110 may have a
thickness in a range of from about 1 micron to about 500 microns.
The thickness of the nanoparticle ink based piezoelectric sensors
110 may be measured in terms of a factor of nanoparticle size of
the nanoparticles and the thickness of first and second conductive
electrodes 114, 118 (see FIG. 2). Thickness of the nanoparticle ink
based piezoelectric sensor 110 may also depend on the size of the
nanoparticle ink based piezoelectric sensor 110, as a proper aspect
ratio may increase the sensitivity of the nanoparticle ink based
piezoelectric sensor 110.
The nanoparticle ink 104 may further comprise an adhesion promoter,
such as a sol-gel based adhesion promoter, a polymer based adhesion
promoter such as an epoxy or another suitable polymer based
adhesion promoter, or another suitable adhesion promoter for
promoting adhesion of the nanoparticle ink to a surface of the
substrate 101 (see FIG. 5). In one embodiment the nanoscale ink
nanoparticles may be suspended in a silica sol-gel and then
deposited using an ink deposition process 122 such as a direct
write printing process 124 (see FIG. 9). The silica sol-gel in the
nanoparticle ink formulation enables the nanoparticle ink to bond
to a wider variety of substrates than certain known adhesion
promoters. The nanoparticle ink based piezoelectric sensor 110
preferably has modalities based on ultrasonic wave propagation and
electromechanical impedance.
Lead zirconate titanate (PZT) nanoparticle ink may be formulated by
methods disclosed in contemporaneously filed U.S. nonprovisional
patent application Ser. No. 13/211,554, titled "METHODS FOR FORMING
LEAD ZIRCONATE TITANATE NANOPARTICLES", filed on Aug. 17, 2011,
which is hereby incorporated by reference in its entirety.
As shown in FIG. 5, the substrate 101 may have a non-curved or
planar surface 136, a curved or non-planar surface 138, or a
combination of a non-curved or planar surface 136 and a curved or
non-planar surface 138. As shown in FIG. 2, the substrate 101 may
have a first surface 103a and a second surface 103b. The substrate
101 preferably comprises a composite material, a metallic material,
a combination of a composite material and a metallic material, or
another suitable material. As shown in the FIG. 2, the substrate
101 may comprise a composite structure 102. The composite structure
102 may comprise composite materials such as polymeric composites,
fiber-reinforced composite materials, fiber-reinforced polymers,
carbon fiber reinforced plastics (CFRP), glass-reinforced plastics
(GRP), thermoplastic composites, thermoset composites, epoxy resin
composites, shape memory polymer composites, ceramic matrix
composites, or another suitable composite material. As shown in
FIG. 3, the substrate 101 may comprise a metallic structure 132.
The metallic structure 132 may comprise metal materials such as
aluminum, stainless steel, titanium, alloys thereof, or another
suitable metal or metal alloy. The substrate 101 may also comprise
another suitable material.
FIG. 6A is an illustration of a schematic view of one of the
embodiments of an ink deposition process 122 and an ink deposition
apparatus 142 for fabricating the nanoparticle ink based
piezoelectric sensors 110 of the disclosure. An exemplary direct
write printing process 124 and direct write printing apparatus 144
are shown in FIG. 6A, which shows the jetted atomized deposition
process 126 and the jetted atomized deposition apparatus 146. As
shown in FIG. 6A, nanoscale ink nanoparticles 106 may be
transferred via an inlet 148 into a mixing vessel 150 containing a
solvent 152. The nanoscale ink nanoparticles 106 are preferably
mixed with the solvent 152 in the mixing vessel to form a
nanoparticle ink suspension 154. The nanoparticle ink suspension
154 may be atomized by an ultrasonic mechanism 158 to form atomized
ink nanoparticles 156. The atomized ink nanoparticles 156 may then
be transferred through a nozzle body 160 and directed through a
nozzle tip 162 to the surface of the substrate 101 for depositing
and printing of the nanoparticle ink based piezoelectric sensors
110 onto the substrate 101.
FIG. 6B is an illustration of a close-up view of the piezoelectric
nanoparticle ink based sensors 110 being deposited onto the surface
of the substrate 101. FIG. 6B shows the atomized ink nanoparticles
156 in the nozzle body 160 and the nozzle tip 162 being deposited
onto the substrate 101 to form the piezoelectric nanoparticle ink
based sensors 110. As shown in FIG. 6B, the nanoparticle ink based
piezoelectric sensors 110 may be deposited onto the substrate 101
in a customized shape 164, such as letters, designs, logos, or
insignias, or geometric shapes, such as circles, squares,
rectangles, triangles, or other geometric shapes, or another
desired customized shape 164. The ink deposition process 122 and
the ink deposition apparatus 142 do not require growth of crystals
166 on the substrate 101. Moreover, the deposited nanoscale ink
nanoparticles 106 contain a crystalline particle structure that
does not require any post processing steps to grow the
crystals.
FIGS. 2 and 3 show embodiments of a deposited nanoparticle ink
based piezoelectric sensor assembly 115. FIG. 2 is an illustration
of a cross-sectional view of one of the embodiments of a deposited
nanoparticle ink based piezoelectric sensor assembly 116 that is
deposited onto a substrate 101 comprising a composite structure
102. The deposited nanoparticle ink based piezoelectric sensor
assembly 116 comprises the nanoparticle ink based piezoelectric
sensor 110 coupled to a power and communication wire assembly 140
acting as an actuator assembly 141 (see FIG. 4). The power and
communication wire assembly 140 is preferably formed of a
conductive ink 168 (see FIG. 4) that may be deposited via the ink
deposition apparatus 142 and via the ink deposition process 122
onto the substrate 101. The power and communication wire assembly
140 acting as an actuator assembly 141 (see FIG. 4) may comprise a
first conductive electrode 114, a second conductive electrode 118,
a first conductive trace wire 112a, and a second conductive trace
wire 112b. The first conductive electrode 114, the second
conductive electrode 118, the first conductive trace wire 112a, and
the second conductive trace wire 112b may be adjacent to the
nanoparticle ink based piezoelectric sensor 110.
FIG. 3 is an illustration of a cross-sectional view of another one
of the embodiments of a deposited nanoparticle ink based
piezoelectric sensor assembly 130 that is deposited onto a
substrate 101 comprising a metallic structure 132. The deposited
nanoparticle ink based piezoelectric sensor assembly 130 comprises
the nanoparticle ink based piezoelectric sensor 110 coupled to a
power and communication wire assembly 140 acting as an actuator
assembly 141 (see FIG. 4). The power and communication wire
assembly 140 is preferably formed of a conductive ink 168 (see FIG.
4) that may be deposited via the ink deposition apparatus 142 and
via the ink deposition process 122 onto the substrate 101. The
power and communication wire assembly 140 acting as an actuator
assembly 141 may comprise the first conductive electrode 114, the
second conductive electrode 118, the first conductive trace wire
112a, and the second conductive trace wire 112b. The first
conductive electrode 114, the second conductive electrode 118, the
first conductive trace wire 112a, and the second conductive trace
wire 112b may be adjacent to the nanoparticle ink based
piezoelectric sensor 110. As shown in FIG. 3, the deposited
nanoparticle ink based piezoelectric sensor assembly 130 further
comprises an insulation layer 134 deposited directly onto the body
of the substrate 101, the substrate 101 comprising the metallic
structure 132. The nanoparticle ink based piezoelectric sensor 110
may be deposited over the insulation layer 134. The insulation
layer 134 may comprise an insulating polymer coating, a dielectric
material, a ceramic material, a polymer material, or another
suitable insulation material. The nanoparticle ink based
piezoelectric sensor 110 is preferably coupled to the power and
communication wire assembly 140.
FIG. 4 is an illustration of a top perspective view of the
distributed network of nanoparticle ink based piezoelectric sensor
assemblies 120. FIG. 4 shows a plurality of the nanoparticle ink
based piezoelectric sensors 110 coupled to the plurality of
conductive ink 168 power and communication wire assemblies 140
acting as actuator assemblies 141, all deposited on the structure
30, such as the composite structure 102. Similarly, for a metallic
structure 132, a plurality of nanoparticle ink based piezoelectric
sensors 110 may be coupled to a plurality of power and
communication wire assemblies 140, all deposited on the metallic
structure 132.
In another embodiment of the disclosure, there is provided a method
200 of monitoring structural health of a structure 30. FIG. 8 is an
illustration of a flow diagram of an embodiment of the method 200
of the disclosure. The method 200 comprises step 202 of providing a
structure 30 to be monitored for structural health 172 (see FIG.
7). The method 200 further comprises step 204 of depositing onto
the structure 30 via an ink deposition process 122 a plurality of
nanoparticle ink based piezoelectric sensors 110 and a plurality of
conductive ink power and communication wire assemblies 140
interconnecting the plurality of sensors 110 to form a distributed
network of nanoparticle ink based piezoelectric sensor assemblies
120.
As shown in FIG. 8, the method 200 further comprises optional step
206 of poling the nanoparticle ink based piezoelectric sensors 110
with a voltage supply source 176 (see FIG. 7) to create an electric
field across the nanoparticle ink based piezoelectric sensors 110.
The method 200 further comprises step 208 of providing electrical
power to the distributed network of nanoparticle ink based
piezoelectric sensor assemblies 120 via an electrical power source
178 (see FIG. 7). The method 200 further comprises step 210 of
using a data communications network 179 (see FIG. 7) to retrieve
and process structural health data 174 (see FIG. 7) of the
structure 30 via one or more signals 92 (see FIG. 5) from the
nanoparticle ink based piezoelectric sensors 110.
The structure 30 preferably comprises an aircraft structure 10 (see
FIG. 1). As shown in FIG. 9, the ink deposition process 122 may
comprise a direct write printing process 124 comprising a jetted
atomized deposition process 126, an ink jet printing process 128,
an aerosol printing process 180, a pulsed laser evaporation process
182, a flexography printing process 184, a micro-spray printing
process 186, a flat bed silk screen printing process 187, a rotary
silk screen printing process 188, a gravure printing process 189,
or another suitable direct write printing process 124. The data
communications network 179 may retrieve structural health data 174
received from the nanoparticle ink based piezoelectric sensors 110
with a receiver 175 (see FIG. 7) and may process structural health
data 174 received from the nanoparticle ink based piezoelectric
sensors 110 with a computer processor 177 (see FIG. 7). The
structural health data 174 may comprise disbonds, weak bonding,
strain levels, moisture ingression, materials change, cracks,
voids, delamination, porosity, and irregularities that adversely
affect the performance of the structure, or other suitable
structural health data 174.
The substrate 101 preferably comprises a composite material, a
metallic material, a combination of a composite material and a
metallic material, or another suitable material. The substrate 101
preferably comprises a first surface 103a and a second surface 103b
(see FIG. 2). The substrate 101 may have a non-curved or planar
surface 136 (see FIG. 5), a curved or non-planar surface 138 (see
FIG. 5), or a combination of a non-curved or planar surface 136
(see FIG. 5) and a curved or non-planar surface 138 (see FIG. 5).
The nanoparticle ink based piezoelectric sensors 110 may be
deposited onto the substrate 101 in a customized shape 164 (see
FIG. 6B).
The nanoparticle ink based piezoelectric sensors 110 may undergo a
poling process with a voltage supply source 176 (see FIG. 7) prior
to being used in the structural health monitoring system 170 for
monitoring structural health 172 of the structure 30. The
nanoparticle ink based piezoelectric sensors 110 may be coupled to
the power and communication wire assembly 140 formed from a
conductive ink 168 deposited onto the substrate 101 via the ink
deposition process 122 prior to being used in the structural health
monitoring system 170. Two or more nanoparticle ink based
piezoelectric sensors 110 may be used to enable the structural
health monitoring system 170.
The structure 30 may comprise an aircraft 10 (see FIG. 1), a
spacecraft, an aerospace vehicle, a space launch vehicle, a rocket,
a satellite, a rotorcraft, a watercraft, a boat, a train, an
automobile, a truck, a bus, an architectural structure, a turbine
blade, a medical device, electronic actuation equipment, a consumer
electronic device, vibratory equipment, passive and active dampers,
or another suitable structure. The system 170 and method 200 may be
used across many industries including, for example, wind power
generation (health monitoring of turbine blades), aerospace
applications, military applications, medical applications,
electronic actuation equipment, consumer electronic products, or
any application where structures or materials require a monitoring
system.
In another embodiment of the disclosure, there is provided a method
of monitoring structural health 172 of a structure 30. The method
comprises providing a structure 30 to be monitored for structural
health 172. The method further comprises using a distributed
network of nanoparticle ink based piezoelectric sensor assemblies
120 to sense and monitor the structural health 172 of the structure
30. The method further comprises providing electrical power to the
distributed network of sensor assemblies 120 via an electrical
power source 178. The method further comprises using a data
communications network 179 to retrieve and process structural
health data 174 of the structure 30 via one or more signals from
the nanoparticle ink based piezoelectric sensor assemblies 120.
Embodiments of the system 170 and method 200 disclosed herein
provide nanoparticle ink based piezoelectric sensors 110 for
structural health monitoring that may be used for a variety of
applications including ultrasonic damage detection for composite
and metallic structures, crack propagation detection sensors,
pressure sensors, or another suitable sensor. For example, the
nanoparticle ink based piezoelectric sensors 110 of the system 170
and method 200 may provide cradle to grave health monitoring of
various components in aircraft such as damage detection for door
surrounds, military platforms such as crack growth detection for
military aircraft, and space systems such as cryo-tank health
monitoring. The nanoparticle ink based piezoelectric sensors 110
may provide structural health data that was previously not
available that may influence new and efficient designs which may
reduce costs.
Using the direct write printing process 124, and for example, the
jetted atomized deposition process 126, along with the formulated
nanoparticle ink, allows many nanoparticle ink based piezoelectric
sensors 110 to be deposited onto a surface of a substrate 101 or a
surface of a structure 30 and at a decreased cost as compared to
known processes of depositing piezoelectric sensors. Embodiments of
the system 170 and method 200 disclosed herein provide nanoparticle
ink based piezoelectric sensors 110 that allow for the placement of
the nanoparticle ink based piezoelectric sensors 110 in numerous
areas of the structure 30 and in large quantities, both of which
may be difficult with known piezoelectric sensors. Moreover,
embodiments of the system 170 and method 200 disclosed herein
provide nanoparticle ink based piezoelectric sensors 110 that are
advantageous over known sensors because they may not require an
adhesive to bond them to the substrate or structure, and this
decreases the possibility that the nanoparticle ink based
piezoelectric sensors 110 may disbond from the structure 30.
Further, embodiments of the system 170 and method 200 disclosed
herein provide nanoparticle ink based piezoelectric sensors 110
that are enabled by the availability of nanoscale ink particles 106
having favorable piezoelectric properties and that are deposited
onto a substrate or structure in a desired configuration for use
without the use of adhesive. Because the nanoparticle ink based
piezoelectric sensors 110 may be deposited onto a substrate or
structure with no adhesive between the sensors 110 and the
substrate or structure, improved signal coupling into the structure
being interrogated may be achieved. Further, embodiments of the
system 170 and method 200 disclosed herein provide nanoparticle ink
based piezoelectric sensors 110 that do not require manual
placement or installation on the substrate or structure and may be
deposited or printed onto the substrate or structure, along with
all the required power and communication wire assemblies, thus
decreasing labor and installation costs, as well as decreasing
complexity and weight of the structure. In addition, the
nanoparticle ink based piezoelectric sensors 110 may be deposited
with numerous direct write printing processes, including the jetted
atomized deposition process 126; may be fabricated from
nanoparticle size particles which have been pre-crystallized and
may be more efficient than known sensors that have not been
crystallized; do not require a high temperature
sintering/crystallization process and thus reduces or eliminates
possible damage to temperature sensitive substrates or structures;
may be deposited onto curved or non-planar substrates or
structures; have no or minimal physical geometry limitations and
thus decreases the possibility of inadequate sensing capacities or
inadequate actuation responses. Further, embodiments of the system
170 and method 200 disclosed herein provide nanoparticle ink based
piezoelectric sensors 110 that may be used to predict deterioration
or weaknesses of the structure 30 prior to the actual development
of such deterioration or weaknesses, and thus, may increase
reliability of the structure or structural component parts, and may
reduce overall manufacturing and maintenance costs over the life of
the structure or structural component parts. Finally, embodiments
of the system 170 and method 200 disclosed herein have the ability
to predict, monitor, and diagnose the integrity, health, and
fitness of a structure without having to disassemble or remove the
structure or drill holes into the structure for insertion of any
measurement tools.
Many modifications and other embodiments of the disclosure will
come to mind to one skilled in the art to which this disclosure
pertains having the benefit of the teachings presented in the
foregoing descriptions and the associated drawings. The embodiments
described herein are meant to be illustrative and are not intended
to be limiting or exhaustive. Although specific terms are employed
herein, they are used in a generic and descriptive sense only and
not for purposes of limitation.
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